Check out page 92 in Manko's Soldering book - it is stated that at soldering temperatures the solubility of Al is less than 0.5%. W.G. Bader also did quite a bit of work on the dissolution of elements in solder but I don't know if he looked at Al - you will have to conduct a literature search using Bader as the key word. You also might try putting a secondary finish on the Al - anodized or nickel plate, etc. to prevent wetting. Good luck. Dave Hillman Rockwell Collins [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: Re: Rate of Aluminium in Solder Bath. Author: [log in to unmask] at ccmgw1 Date: 6/7/96 10:24 AM Dear Technet, Can anybody advise me what is the rate of Aluminium dissolve into the solder (63/37) bath. I'm using Alu Stiffener to prevent the PCB from warping. How can use PTFE to coat it. Is there any spray type and where can I can it ? Poh Kong Hui Nera Electronics Email: [log in to unmask]